Fundamental Radiation Physics and Particles

The smallest unit of an element that retains the chemical properties of that element. They are incredibly small, even the most powerful optical microscopes can't see them directly.

Subatomic particles found in the nucleus of an atom. They have a neutral charge and contribute to the atom's mass.

Subatomic particles found in the nucleus of an atom. They have a positive charge and contribute to the atom's atomic number.

Negatively charged subatomic particles that orbit the nucleus of an atom in specific energy levels or shells. They determine the atom's chemical properties.

The central part of an atom containing protons and neutrons. It has a positive charge and is responsible for the atom's mass.

The number of protons in the nucleus of an atom. It defines the element's identity and its position in the periodic table.

The total number of protons and neutrons in the nucleus of an atom. It determines the atom's mass and isotope.

A specific type of atom characterized by its unique combination of protons and neutrons. It defines an atom's identity and its properties.

The total amount of energy contained in a system, measured in Joules.

The mass of an object, measured in kilograms (kg).

The speed of light in a vacuum, a constant value approximately equal to 3 x 10^8 meters per second.

The relationship between the energy of a wave and its frequency. It states that the energy of a wave is directly proportional to its frequency, meaning a higher frequency wave will have a higher energy.

The number of wave crests that pass a fixed point in one second, measured in Hertz (Hz) or per second (s^-1).

The distance between two successive crests or troughs of a wave, measured in meters (m).

The speed at which a wave propagates through a medium, measured in meters per second (m/s).

The relationship between wavelength, frequency, and propagation velocity of a wave. It states that the product of wavelength and frequency is equal to the propagation velocity.

Energy that travels in waves or as streams of particles. It can be classified as non-ionizing or ionizing based on its ability to remove electrons from atoms.

Radiation that has enough energy to cause atoms to vibrate but not enough to remove electrons. Think radio waves, microwaves, and infrared radiation.

Radiation that has enough energy to remove electrons from atoms. Think X-rays and gamma rays.

The full range of electromagnetic radiation, encompassing radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. It's characterized by different wavelengths and frequencies.

A form of electromagnetic radiation that travels at the speed of light in a vacuum, encompassing radio waves, light, and cosmic rays. It's energy released from stars and other celestial bodies.

The ability of a substance or material to absorb energy. It's measured in units like joules per mole or electron volts.

The speed at which electromagnetic radiation travels in a vacuum, approximately 299,792 kilometers per second. It's a fundamental constant in physics.

The interaction of radiation with matter that results in the transfer of energy. For example, light shining on a surface warms it up.

The process where electrons are emitted from a heated surface, like a filament, due to the high kinetic energy causing them to overcome the work function of the material.

The energy of electrons in a beam is primarily converted into heat (99%), with only a small percentage (1%) being converted into X-rays. This heat generation is a major challenge in X-ray tube design.

The area on the target of an X-ray tube where the electron beam hits. It determines the size and shape of the resulting x-ray beam.

The size of the focal spot directly affects the resolution of the X-ray image. Smaller focal spots produce sharper images.

The process of removing excess heat from the X-ray tube target, crucial for preventing damage and maintaining tube performance.

Occurs when an electron dislodges an electron from an inner shell of an atom, creating a vacancy. This triggers the emission of characteristic X-rays.

The energy required to create a vacancy in an inner electron shell of an atom by removing an electron.

The specific energy levels within an atom's electron shells. They determine the energy of the emitted characteristic X-rays.

The energy lost by the X-ray is effectively transferred to the electron, giving it kinetic energy. The energy of the scattered X-ray (E') is slightly less than the incident X-ray (Ex-ray) due to this energy transfer.

The relationship between the initial wavelength of an X-ray (λ) and its wavelength after scattering (λ') is directly proportional to the scattering angle (θ). This means the larger the angle, the greater the wavelength shift.

The Compton wavelength is a characteristic length scale related to the electron's mass. It represents the minimum change in wavelength that can occur during Compton scattering.

The energy of the scattered X-ray is always less than the incident X-ray due to the transfer of energy to the electron.

The Compton effect demonstrates that X-rays can behave as particles (photons) that interact with electrons in a scattering process. This supports the wave-particle duality of light.

The kinetic energy of an incoming electron, represented by 𝑘𝑜, is equal to the potential energy between the cathode and target, expressed as 𝑒𝑉𝐶𝑎𝑡ℎ𝑜𝑑 →𝑇𝑎𝑟𝑔𝑒𝑡.

X-ray photons exhibit quantization, meaning their energy can only exist in specific discrete values. The maximum energy of an X-ray photon (ℎ𝑣𝑚𝑎𝑥) is directly proportional to the potential difference between the cathode and target. The formula ℎ𝑐 / 𝑒𝑉𝐶𝑎𝑡ℎ𝑜𝑑 →𝑇𝑎𝑟𝑔𝑒𝑡 describes the relationship between energy and potential difference.

The minimum wavelength (𝜆𝑚𝑖𝑛) of the emitted X-rays is inversely proportional to the potential difference between the cathode and target. The formula ℎ𝑐 / 𝑒𝑉𝐶𝑎𝑡ℎ𝑜𝑑 →𝑇𝑎𝑟𝑔𝑒𝑡 expresses this relationship.

When an electron interacts with the nucleus of a target atom, it can slow down or change its direction, losing some or all of its kinetic energy. This loss of energy is emitted as X-ray photons, known as bremsstrahlung, or 'braking radiation', creating a continuous spectrum of X-ray energies. This spectrum is known as the continuous X-ray spectrum.

The continuous X-ray spectrum results when an incident electron loses energy as it interacts with the target nucleus. The energy loss directly corresponds to the energy of the emitted X-ray photon.

The maximum energy (ℎ𝑣𝑚𝑎𝑥) of an X-ray photon occurs when the incident electron loses all of its initial kinetic energy (𝑘0). This energy loss is equal to the energy of the photon: |∆𝑘| = |−𝑘0 | = ℎ𝑣𝑚𝑎𝑥.

The minimum wavelength (𝜆𝑚𝑖𝑛) of the emitted X-rays depends only on the initial kinetic energy (𝑘0) of the incident electron and is independent of the target material. This is because the minimum wavelength is directly related to the maximum energy of the emitted photons.

The characteristic properties of the continuous X-ray spectrum, such as its intensity distribution, are influenced by the target material. Different materials absorb and emit X-ray photons differently.